This invention relates to a method for the coloring of organic materials, especially textiles, with naphthacenequinone derivatives.
The prior art has made little use naphthacenequinone derivatives as dyestuffs. It has been disclosed that the sulfonated compound obtained by the treatment of a naphthacenequinone derivative with concentrated sulfuric acid can be used as the acid dye for wool, in the journal of the Chemical Society, Vol., 91, 411-435 (1907), but the structure of the sulfonated naphthacenequinone derivative was not described. Furthermore, from the fact that these derivatives are not described in "Colour Index, 2nd Edition (1956) and its Supplement (1963)" edited by the Society of Dyers & Colourists and the American Association of Textile Chemists and Colourists or in "The Chemistry of Synthetic Dyes, Vol. I & II (1952) and Vol. III (1970)" written by K. Venkataramann, etc., it is obvious that the new naphthacenequinone derivatives have not been commercially used at all as dyestuffs. It has now been discovered, as a result of intensive colorant tests on organic materials colored with the new naphthacenequinone derivatives, that the compounds of formula (I) (below) colored the organic high molecular weight compounds in brilliant nuance with characteristic fluorescence and high sublimation fastness.
The present inventors, have previously discovered that certain naphthacenequinone derivatives can be effectively used as dye for the coloring of organic materials (US application no. 379,482 filed on July 16, 1973). The remarkable difference between the previous invention and the present one is as follows:
The novel compounds of the present invention have unexpected sublimation fastness compared to the compounds of the previous invention, for example, the sublimation fastness of yellow-red dyeings with the compounds of the present invention is higher, 1-2 grades than the value of the yellow-red dyeings with the compounds of the previous invention as shown below.
______________________________________ Shade of Polyester Sublimation Invention Compound dyed article fastness ______________________________________ Present Invention ##STR2## Yellow 4-5 Previous Invention ##STR3## " 2-3 Previous Invention ##STR4## " 3 ______________________________________
besides, .alpha.-aminoanthraquinone, the most important intermediate for reddish disperse anthraquinone dye, is produced at present by amination of anthraquinone-1-sulfonic acid obtained by sulfonation of anthraquinone in the presence of mercury catalyst. Recently, the need to avoid environmental pollution by mercury has become an intense problem in the chemical industry. The new naphthacenequinone derivatives used in this invention be obtained without using mercury and can color in more brilliant nuance and with higher sublimation fastness than the anthraquinone derivatives.